Soluble anti‐μ monoclonal antibodies prime resting B cells to secrete immunoglobulins in response to interleukins‐4 and ‐5

摘要

AbstractSoluble anti‐immunoglobulin (Ig) antibodies have been generally found to inhibit Ig secretion in B cells, via largely unknown mechanisms. To investigate this phenomenon further a two‐step culture system was used in which B cells are primed for24–72 h with various soluble monoclonal or polyclonal anti‐Ig antibodies: after washing the cells were placed in readout cultures with a combination of interleukin (IL)‐5 and IL‐4. Using this protocol B cells primedwith (mitogenic ornonmitogenic) anti‐μ monoclonal antibodies differentiated into large numbers of IgM‐secreting cells, comparable to responses to lipopolysaccharide. In contrast, priming with polyclonal rabbit anti‐Ig or monoclonal anti‐x antibodies, markedly inhibited Ig secretion induced by IL‐4 + IL‐5. In addition, anti‐μ was markedly inhibitory if left in thereadout cultures with the two lymphokines. These results, therefore, indicate that appropriate cross‐linking of surface IgM receptors on B cells can prime the cells tosecrete Ig when they are restimulated by T cell‐derived lymphokines in the absence of anti‐μ. Incontrast co‐ligation of both surface IgM and surface IgD receptors apparently results in powerful inhibition of Ig secretion, which is not revers